Acoustical device



Nov. 16 1926.

A. V. BODINE ET AL ACOUSTICAL DEVICE Filed May 24.

1924' 2 Sheets-Sheet 1 INVENTORS WITNESS E U w E m mm 0, 0% w. A v M Y mp U RE Fs MO 6 W. yw

A. v. BODINE ET AL ACOUSTICAL DEVICE Nov. 6, 1926.' 1,606,744

Filed May 24, 1924 2 Sheets- Sheet '2 WITNESS .INVENTORS I 4, ALFRED v. BOD/NE 7Z2. OJOSEPH M. LUCARELLE Patented Nov. I 16, 1926.

UNITED STATES PATENT O FICE.

ALFRED v. nomNn AND JOSEPH M. LUCARE-LLE, or BRIDGEPORT, CONNECTICUT, As- SIGNORS To DICTAPHONE CORPORATION, or BRIDGEPORT, CONNECTICUT, A COR- PORATION OF NEW-YORK.

ACOUSTICAL nnvICE.

Application filed May 24, 1924. Serial NO. 715,562.

Thisinvention relates to improvements in sound recording, sound reproducing, and sound recording and reproducing mechanisms,.for phonographs, et cetera.

One embodiment of the invention, shown as applied to dictation machines, ,is illustrated in the accompanying drawings, in which- Figure 1 is an end view, partly in section, of an improved sound recording-reproducing mechanism fora dictating machine, made in accordance with this invention, showing the parts in-the positions they occupy when recording.

Fig. 2 is a sectional view, of the speakerhead, with the parts in positions they 'occupy when reproducing.

Fig. 3, is a bottom plan view of the speaker-head, with the casing broken-away to show the details of construction.

In the form shown in the accompanying drawings, the recording and reproducing mechanism comprises a carriage 10, Fig. 1, slidablymounted on a guide 11 to travel over a record 12 which is rotated coincidently with the traveling movement of the carriage so that the knife-like recording stylus13 produces a spiral groove in the' surface of the record and records the sound therein. This may then be reproduced by engagement ofa ball-like reproducing stylus 14: in the spiral groove, all in the usual and common manner. L

The recording stylus 13 and reproducing stylus 14: are mounted in a holder 15 secured to a diaphragm 16 by a screw 17 passing through a perforation in the diaphragm. The diaphragm, which ispreferably a mica disk, is mounted in a casing 18 havin a d shed-portion 19 to receive it. Spacing the diaphragm from the face of the dishedportion is a spacing-washer or annulus 20 against which the diaphragm is held by a fillet 21 of plastic material such as bees wax engaging the casing 18. i The diaphragm casing or speaker 18 is provided with a tube 22 extending into a housing 23 which is secured. by screws 24 to the carriage 10, and is mounted, as hereinafter described, for longitudinal movement substantially tangentially of the record, in a tube 25, itself slidably mounted in the hous ing 23. This tube 25 is-held against turning I movement in the housing 23 by a pin '26 mounted in a hole in the latter and passing through a slot 27 in the tube'25.

To move the tube 25, and with it the speaker 18, for the purpose of shifting from recording position to reproducing position or vice versa, or to an intermediate position where neither of the styli engages the record, a -manually operable control lever 29- 'is provided. This lever 29 is mounted on the carriage and has a link 30 pivotally mounted thereon at 31 and having at its other end a hook 32 engaging the end wall -28 of the slot 27 The rocklng movements of the lever 29 arp transmitted to the sliding tube 25 in the form of reclprocatory movements which cause the position of the tube to be changed as desired to bring either the stylus 13 or the stylus 14; to record-engaging position when the lever is in'its respective extreme forward or backward position.

In its intermediate position, the speaker 18 is held elevated'with respect to the recordsurface, with neither of the styli 13 or 14 engaging the record, by the engagement of a cam-surface 33 on the speaker with an abutment 34*,on the housing 23. Further, the cam33 and abutment 34: serve to lift the styli on the. speaker away from the record as soon as the speaker starts to move from either of its operating positions, and this avoids damage being done to the record by the sliding movement of the styli Over its surface.

A In addition to the movement above referred to, the recorder-reproducer mechanism is also movablevertically to accommodate itself to records of various sizes, depending upon the extent to which they have been previously used and shaved, and to permit slight vertical movements in operation due to eccentricity-of the record on its support; It is also necessary, in reproducing, to provide for slight lateral movement of the reproducing stylus so that it will follow with freedom the grooves previously made in the record surface, without damaging the side walls of the grooves by undue pressure on either slde.

. er 18, being Thus, it will be seen, the recorder-repro- .ducermoves longitudinally, laterally and vertically. Y This universality of movement of the speaker with relation to its mounting is provlded for by a gimb'lemounting comprising a horizontal pivot to allow vertical move ment, a vertically pivoted supportfor the horizontal pivot to allow horizontal movement, and slidable means for supporting the vertically pivoted support.

The horizontal pivot, it has been-found may advantageously comprise a pair of pivot pins or cone-point screws 36, Fig. 3, engaging centers provided in brass or other suitable bushing 37 driven into apertures in an enlarged end 380i the tube 22, which tube is preferably made of aluminum for lightness. Thecone-point screws 36,.engage the end 38 at diametrically opposite points and allow only vertical movements of the speaker 18; they do not pass into the sound passage of the tube 22 and, therefore, in no way interfere with-the sound transmission. The screws 36 are-threaded into a tubular support 39 surrounding the enlarged end 38 of the tube 22 and can be adjusted therein' to accurately engage and support the speaklocked in adjusted position by lock-nuts 40.

The horizontal movement of the speaker 18 is permitted by providing the tubular support 39 with a pivotal connection to the sliding tube 25. This connection comprises a pair of trunnion-screws 41 (Fig. I 2) threaded into the tubular support 39 and having round bearing-heads 42 fitting openings 43 provided in the sliding tube 25. These trunnion screws 41 are located diametrically opposite each other and at right angles to the screws 36. i

The trunnion screws 41 when so provided are applied from the outside of the assembled unit comprising the speaker 18 and sliding tube 25 and this arrangement has been found to facilitate the assembling of these parts. Likewise, and with similar advantage,the screws 36, also may be applied and adjusted from the outside of the assembled unit, the sliding tube 25 having an 'openlng 44 adjacent each screw into which the end of the screw 36 extends and in which the lock nut is located.

For the purpose of applying sufficient Weight to the speaker 18 during reproduc ing, so that the Wave-like surface of the record-groove in which the sound is record-- ed will not merely cause the speaker 18 to oscillate,,but will properly cause the diaphragm to vibrate, a weight 45 mounted be tween arms 46 isv adapted to bear against the upper surface of the speaker-casing 18 through a sound-deadening plug 47 of leather. The weight-arms 46 are mounted upon theends of the bushing 37 and are tube 25 on one side,'and the end'38 of the speaker-tube 22 on the other side, so as to .avoid the loss of a substantial part of the sound energy received by the nozzle 35,

which would resultin making a weak rec-,

0rd. Even the closest fit commercially practicable, was found to.allow the; escape of so much sound energy that, in many in-, stances ,a very thin, sensitive diaphragm had to be employed to satisfactorily record the sound ultimately reaching the diaphragm. Such diaphragms were not acoustieally correct and the best results were not obtainable, because the diaphragms natural vibration period was much higher than the vibratory periods of the sounds ordinarily desired to be recorded. Moreover, a space or pocket P was produced between the' sliding tube 25, the speaker and connected parts,

the parts were in recording position (Fig.

.1), and this. pocket P acting as a resonator changed the character of the sound, giving a tubby effect in many-instances.

, i To avoid these disadvantages and toreduce the cost of manufacture of the record- .er-reproducer, this invention provides a 35 provided on the housing23,

and the wall 49 of the housing 23, when tube 50 directly interconnecting the nozzle 35 and the speaker-tube 22. The nozzleend ofthe tube 50 slides upon the internal surface of the nozzle 35 and maintains its- "connection therewith in all positions of the speaker 18. At its speaker end the tube 50 snugly fits within the enlarged end 38 of the speaker-tube 22 and is held therein by engagement with studs or trunnions 51 provided on the ends of the bushings 37, holes 52 being provided in the tube 50 to enga e the trunnions 51. These are ,sufiici-ent y large to permit some freemovement of the tube 50 relative to the tube 22 of the speaker to allow horizontal movement of the speaker tube 22.

The diameter of the passage of each of the parts, the connecting tube 50 and the tube 22 of the speaker, gradually reduces from the nozzle 35 to the diaphragm 16 so that the sound is confined as it passes to the diaphragm; and it is'to an appreciable .extent intensified by this confining action.

Ill

Withthis provision, any desired clearance or space 53 may be provided between thesliding tube 25 and the tubular support 39. Also anydesired clearance 54 between the tubular support 39 and the end 38 of the speaker-tube '22 may be providfed,'and thus the tolerances (that is to say the permissavin in time and labor sible departure from stated-requirements) in the manufacture of the mountings may be materially increased. with an accompanying in the manufacture of the parts. Y

Whilethere has been herein described in detail one embodiment of this invention, it should be understood that other embodi- '-ments will suggest themselves to those skilled in the art, and that variations and modifications may be made within the scope of the appended claims, and portions of the improvements may be used without others.

Having now described the invention, what is claimed as new, and for which Letters Patent is desired, is: i I

1. In combinatlonya diaphragm-carrying member made of light-weight relatively soft material; a carrier for'the member; cone shaped studs in the carrier for pivotally supporting the member; and relatively hard, Wear-resisting bushings inserted in the member, adapted to be engaged by the coneshaped studs for pivotally supporting the member.

2. In combination, a diaphragm-carrying member;'a carrier for the member; means in the carrier for pivotally supporting said member; bushings inserted in the member adapted to be engagedby the means for pivotally supporting the member; a weight: member adapted to engage the diaphragmcarrying member; and means on the bushings to pivotally support the weight-memer. 3. In combination, a tubular diaphragm-- carrying member; a carrier for the member; means in the carrier for pivotally: support ing the member; bushings inserted in the member adapted to be engaged by the means for pivotally supporting the member; a

tubular sound-conductor extending within the tubular diaphragm-carrying member adjacent its pointof support; and studs on the bushings to connect the tubular sound-conductor to the tubular diaphragm-carrying member. V

4. In combination, a tubular diaphragmcarrying member; a carrier for the member; means in. the carrier for pivotally supporting the member; bushings inserted in the member adapted to be engaged by the means for pivotally supporting the member; a weight-member adapted to engage the diaphragm-carrying member; shoulders on the ushings adapted to pivotally support the weight-member; atubular sound-conductor connecting with the tubular diaphragmcarrylng member adjacentits point of sup- ,port; and studs on the bushings to connect the tubular sound-conductor to the dia phragm-carrying member.

5. In combination, a sound-conductor; a carrier for the sound-conductor; means in the carrierfor pivotally supporting the sound-conductor; bearing means in the sound-conductor adapted to be engaged by the means for pivotally supporting the sound-conductor; an auxiliary sound-conductor extending within the first-named sound-conductor adjacent its point of support; and means on the bearing means adapted to connect the auxiliary Sound-conductor to the first-named sound-conductor.

6. .In combination, a sound-conductor; acarrier for the sound-conductor; means 1n the carrierfor pivotally supporting said sound-conductor; bearing means in said,

sound-conductor adapted to-be engaged by the means for pivotally supporting the sound-conductor; a weight-member adapted to engage the sound-conductor; means on the bearings adaptedto pivotally support the Weight-member; an auxiliary sound-conductor connecting with the. first-named sound-conductor, adjacent its point of support; and means on the bearings adapted to connect the auxiliary sound-conductor to the first-named sound-conductor.

7-. In a phonograph, a member, means permitting said member to have lateral play; means permitting saidmember to have vertical play, said member carrying a diaphragm provided with a recording-stylus and a reproducing-stylus andhaving a" sound-conduit leading tow the dlaphragm; a

housing in which said member is mounted-y sound-receiving means on said housing; and

.THGELDS for conveying the sound received by pivotal po- 9. In combination, a member havingsound-passage therefor; a diaphragm at one end of the sound-passage; said sound-passage having an enlarged end at the other end of the sound-passage; a housing in which said member is mounted for longitudinal and lateral movement, saidhousing having a sound-receiving orifice, the enlarged end of said member being movable to and from said orifice; and a tube in in timate contact with said orifice and extending into the enlarged end of said member, to prcvide a closed and continuous path for the sound from said orifice to said enlarged end of said member.

10.-In combination, a sound-conducting.

means; a carrier therefor; means for pivotally supporting, said means on said carrier for movement in one plane; a support for the carrier; means for pivotally supporting the said support for movement in a plane common to the first named plane; a housingin which said support 1s mounted; sound-receiving means at a part of the housing removed from the sound-conducting means; and means for directlytransmittlng sound 'fromsaid sound-receiving means to otally supporting .said means in said carrier for movement in one plane; a support for the carrier; means for plvotally supporting the support for movement in a plane commonto the first named plane; means for guiding the last-named means for longitudis nal movement; sound-receiving means on the t last-named means, remote from the soundconducting means; and means for directly transmitting sound from said sound-receiving means to the relatively movable sound-.

conducting means.

12. In combination, sound-conducting means; a carrier therefor; means for piv the said supportfor pivotal movement in a plane common to the first named'plane; a 'casing in which said'support is-mounted; sound receivingm'eans at a part of the casing removed from the sound-conducting means; and means for directly transmitting sound from said sound-receiving means to the sound-conducting means.

ALFRED v. Booms. aosnrn M. LUoAnELLn 

